69 Z/28 Day II Project (Air Force Brat)

[NorCam]

Morning Freddie...

A couple of things on this trans case if I may? Firstly, it has a 10 spline input with a nut and does not have an internal oil seal input, therefore it vents through the threads of the nut and has no need for the addition of a rear vent. It has 1 quart of driven gear oil for break-in and in talking with Nate at AGE last year, he schooled me on the approved oils for their gearboxes. He also gave me a list of which oils they were sold on. Amsoil MTG was on that list as were other ML-1 rated GL4/5 synthetics including Royal Purple Max Gear, Redline MT-90, and some others.

FWIW...my preference (much like Nathan's) lays with petroleum-based oils such as Joe Gibbs and Brad Penn and I would offer that it is all relevant to how you are going to use a gearbox, or should I say...how you plan to punish it. Different oils shift better at higher RPM, while others don't work well when downshifting from 4/3, and some are friendlier to bronze and brass than others are but are also subject to change when they add or delete friction modifiers and formulas from year to year. There's no one magic bullet IMO.

At present, I'm OK with the Driven gear oil for the break-in but may change to something else when that's complete. Thank you for the cautionary warnings. It's all good information.